Hydraulic ratchet wrench



May 23, 1950 w. v. ELLISON HYDRAULIC RATCHET WRENCH 2 She ets-Sheet 1 Filed June 6, 1947 IN VEN TOR. %//a ce Viz/m0 ATTORNEYS y 1950 w. v. ELLISON 2,508,568

HYDRAULIC RATCHET WRENCH Filed June 6, 1947 I 2 Sheets-Sheet 2 mul IN VENTOR.

ATTOR/VEVJ Patented May 23, 1950 UNITED STATES PATENT OFFICE This invention relates to improvements in wrenches, and more particular to an improved ratchet-type wrench having hydraulic operating means incorporated therein.

It is among the objects of the present invention to provide an improved ratchet-type wrench which can be used to turn a bolt or nut in spite oi. obstructions that preclude the operation of an ordinary ratchet wrench by limiting movements of the wrench handle to an amount insuflicient to operate the wrench, which is capable of applying a bolt or nut turning torque substantially as great as can be applied by an ordinary ratchet wrench of equivalent size, which can be used as a hydraulically operated wrench or an ordinary ratchet wrench as may be most convenient under the particular circumstances of use, which is positively reversible, simple, durable and economical in construction, and no more difficult to use than an ordinary ratchet wrench.

Other objects and advantages will become apparent from a consideration of the following description in conjunction with the accompanying drawings, wherein:

Figure 1 is a longitudinal sectional view of a wrench illustrative of the invention.

Figure 2 is a side elevational view of the wrench, a portion being broken away and being shown in section to better illustrate the construction thereof.

Figure 3 is a transverse section on the line 3-3 of Figure 1.

Figure 4 is a transverse section on the line 4-4 of Figure 1.

Figure 5 is a plan view of the wrench head with the detachable cover plate removed.

Figure 6 is a side elevation of a piston head illustrated in Figure 1 and constituting an operative component of the wrench.

Figure '7 is an elevation of a hydraulic cylinder or core member; and

Figure 8 is an elevation of a plunger operative in the core shown in Figure '7, a portion being broken away and shown in section to better illustrate the construction thereof.

With continued reference to the drawings, the wrench has a tubular handle III of cylindrical shape which receives in one end portion a tubular core II having a bore I2 extending therethrough and a counterbore I3 in one end portion thereof. The core II is slidable into the handle III and has a close turning fit therein. A set screw I4 threaded into an aperture in the handle extends into a annular groove I5 in the core to maintain the core in operative association with u the handle against relative longitudinal movement.

The counterbored end of the core II extends beyond the handle and. is externally screw threaded to receive a hollow wrench head I6 which may be of conventional shape having a tapered end portion I'I flaring out from the associated end of the handle I0 and a rounded outer end portion I8, this head being rotatable together with the core I I relative to the handle I0.

A sprocket I9 is journaled in the wrench head by the integral bosses 20 received in the apertures in the base H of the head and in the removable cover plate 22. The sprocket I9 is provided with peripheral ratchet teeth 23 selectively engageable by a pair of dogs 24 and 25 mounted in the head I6 for operative engagement with the sprocket in a manner presently t be described. t

A piston 26 is slidably received in the counterbore I3 and provided at its inner end with a leather cup seal 21 secured to the piston end by a conventional screw 28. The opposite end of the piston 26 is externally screw threaded and inserted into a cylindrical head 29 which overlies the end of the core II surrounding the counterbore. The outer face of this head is provided with a pair of rounded indentations 30 particularly shown in Figure 6, separated by an extension 3| providing a shoulder 32 and a guide 33 for a piston-retracting-compression spring 34 one end of which bears against the shoulder 32 and the opposite end of which bears against an abutment 35 secured to the base 2| of the wrench head. The ends of the dogs 24 and 25 opposite the ratchet tooth engaging ends thereof are seated respectively in rounded depressions 30 in the-piston head 29 and are controlled by suitable reversing means to reverse the direction of rotation of sprocket l9 by selectively bringing the dogs 24 and 25 into engagement with the teeth 23. The reversing means comprises an arm joined at one end to the piston head 29 and extending toward the sprocket I9. An apertured boss is provided at the end of this arm opposite .the head, and a mounting pin 38 is journaled in this boss and projects through an elongated slot 6| in the side plate 22 of thewrench head, so that the pin can move with the piston head 29. Each of the dogs 24 and 25 carries a laterally-extending pin, 62 and 63 respectively, positioned at substantially equal distances from the ends of the dogs resting on piston head 29. A yoke 36 is secured at its mid-length location to the end of mounting pin 38 adjacent the'dogs, and has near through movement of the handle. If it is desired to use the improved wrench as an ordinary ratchet wrench, the handle 44 may be locked in inoperative position by the lock cap 5| and the dogs 24 and 25 may then operate to engage the sprocket and rotate it with the wrench handle and wrench head in the conventional manner.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are, therefore, intended to be embraced therein.

What is claimed is:

1. A wrench comprising a tubular handle, a core in said handle having an externally-screwthreaded portion extending outwardly from one end of the handle and having a bore therethrough and a cylindrical counterbore in one end thereof, means operatively connecting said handle and said core for relative co-axial turning movement while precluding relative lengthwise movement, releasable locking means carried by said handle and engageable with said core to restrain said core and handle against relative turning movement, a hollow, open-sided wrench head received on the projecting end portion of said core and abutting the corresponding end of said handle, a sprocket journaled in said head and having peripheral ratchet teeth, a piston slidable in said counterbore having a head overlying the corresponding end of said core and a pair of rounded depressions in the outer face of said head, a pair of oppositely-acting dogs having their adjacent ends supported in said depressions and their opposite ends engageable with said ratchet teeth, a detachable side plate closing the open side of said wrench head, means extending through said side plate operative to selectively bring either one of said dogs into engagement with and move the other dog away from said ratchet teeth, a compression spring in said head operative to force said piston to its innermost position in said counterbore, a plunger in the end of said bore opposite said counterbore, a body of hydraulic fluid in said bore between said piston and said plunger, and a plunger-operating lever pivotally mounted on said handle and operative upon said plunger l to force hydraulic fluid from said bore into said counterbore to project said piston and thereby actuate the dogs in engagement with said ratchet teeth to turn said sprocket.

2. A Wrench comprising a tubular handle, a

Number sprocket journaled in said head and having peripheral ratchet teeth, a pair of dogs supported in said head and selectively engageable with said ratchet teeth to turn said sprocket in corresponding direction, a piston in said counterbore having a head operatively supporting said dogs, a plunger in the end portion of said bore opposite said counterbore having an end area less than the end area of the said piston, a body of hydraulic fluid in said core between said piston and said plunger, and a manually-movable lever mounted on said handle and operatively associated with said plunger to move said plunger in said bore and thereby impart sprocket-turning movement to said piston.

3. A wrench comprising a tubular handle, a core in said handle having a bore extending therethrough and a counterbore in one end portion, a hollow wrench head secured to said core at the end thereof having said counterbore, a sprocket journaled in said head and having peripheral ratchet teeth, a pair of dogs supported in said head and selectively engageable with said ratchet teeth to turn said sprocket in corresponding directions, a piston in said counterbore having a head operatively supporting said dogs, a plunger in the end portion of said bore opposite said counterbore having an end area less than the end area of the said piston, a body of hydraulic fluid in said core between said piston and said plunger, a manually-movable lever mounted on said handle and operatively associated with said plunger to move said plunger in said bore and thereby impart a sprocket-turning movement to said piston, and lock means carried by said handle and engageable with said lever to lock said lever in inoperative position adjacent said handle.

4. A ratchet wrench comprising a tubular handle, a wrench head secured to said handle, a sprocket in said head, oppositely-acting dogs in said head operative to selectively lock said sprocket to said head for turning movement therewith in either direction, hydraulic means in said handle operatively associated with said dogs to rotate said sprocket in either selected direction when said handle is maintained against movement, and manually-movable means carried by said handle and operatively connected with said hydraulic means for manual actuation of said hydraulic means.

WALLACE V. ELLISON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Name Date 1,913,669 Heald June 13, 1933 2,009,409 Parker July 30, 1935 

